Could be all of the above, but as usual it depends. With Merason I’d expect fuller, richer tonality, more refined treble, and an expanded soundstage. Digital cables matter so don’t skimp there. Here is one I’d recommend as it offers materials/design features (separate data/power legs, 5N silver, Litz construction, Teflon insulation) normally found in much pricier cables.
https://www.lavricables.com/cables/ultimate-silver-dual-usb-a-b-interconnect-cable/
A better streamer with a linear power supply is a worthy upgrade, and upgrading the power supply to your DAC with something from LHY, SBooster, or Teddy Pardo is also very worth considering (should be much cheaper than the Merason power supply). Yeah, it never ends. Just my $0.02 FWIW.